When I tried to argue the point, I was told that most divers just don't care...
I suppose that it's not a matter of whether the diver cares or not. Like in any business, the operator will possess various degrees of professionalism. Some will try to get by with the least amount of safety by way of procedure or equipment in the effort to maximize profits; while others will not.
It can come down to a matter of civil litigation and the operator will be required to answer if they provided a reasonable level of safety for their Clients. Liability is assessed by act (what was done) or omission (what was not done that was reasonable to do). Unfortunately, some loss to life, injury or property has to be first suffered.
I've testified as an expert witness in various court cases and in many cases, the operator was found liable for not providing those reasonable necessities (such as O2, certified O2 Provider and qualified DM). The operator has a fiduciary responsibility to their Clients. How this is interpreted will of course depend upon the jurisdiction.
Like diver certification, there are operators who teach as little as possible. This minimalistic viewpoint runs rampant in many aspects of Society. The Dollar rules everything. Most consumers want to spend as little as possible and the term value often has little meaning.
Despite this, there are still those that refrain from teaching minimal training courses and operators (which I suspect that you are among them) that provide professional services of superior quality to their Clients. Unfortunately there are some Clients that this will be wasted on, but it is at least recognized by those who provide those services and have a professional pride in their efforts.
